Boulder rough opal sellers take picture of the boulder rough dipped in water so the image will expose the colours of the stone as if it was polished. Buyer will receive the boulder or Koroit opal rough in a dry condition.
Boulder opal Rough is mined in Queensland Australia.
It is formed as veins in ironstone. Ironstone is the deep brown potch like stone that is very strong.
Most popular opal mining towns are Quilpie and Winton and many old fields like Jundah or Hammonds mine still produce opal.
Boulder opal mining is capital expensive with large bulldozers and excavators..D9 bulldozers are common and some fields now have D12s as these dozers sometimes have to level off mountain tops to get to the opal and need large strong rippers to break open the ground. the miner will block out the rough opal and when he sees vein of opal colour he will hold against thin saw blade to place nick in the colour and the piece will break open evenly exposing opal colour, sometimes good colour sometimes very little colour
Source your Boulder opal rough direct from opal miners and opal wholesalers and dealers for your single gem opal boulder rough or parcel rough boulder opals from Quilpie or Winton Australia The boulder opal miners hold their annual opal show in Winton in 1st week July. Boulder opal is unique only to Queensland. It only occurs in deposits in weathered sedimentary Cretaceous rocks in the west of the state of Qld.Jundah Opal rough is also located in central Queensland opal fields.
The Term Matrix opal is where the opal occurs as a network of veins or infilling of voids or between grains of the host rock (ferruginous sandstone or ironstone) Opalised wood and pipe opal is occasionally found also Large opal mines often have several bulldozers over large opal leases and partake in extensive exploration for new opal mining fields
Good Boulder or Koroit opal rough should only be cut by Opal professionals as the chance of new opal cutter rubbing good opal colour away is high. we suggest new opal cutters get good lapidary equipment and practise on smaller parcels before cutting good boulder opal rough .Source your Boulder rough singe opals direct from opal miners and opal wholesalers and dealers for your single rough gem opal from Queensland Australia. Boulder rough can have thin colours on top of ironstone so opal cutter must be very gentle in polishing these thin colour bars or color will be rubbed off. For new opal cutters it is recommended to cut matrix or Koroit rough before attempting thin color bar veins in boulder opals, as ,many boulder opal specimens have thin colour bars.
Most opal miners will exchange parcel boulder rough opal or single rough boulder if buyer is not satisfied with parcel but if buyer snips or works and opal the parcel is yours and cannot be returned.
Opal miners ,opal suppliers and opal wholesalers offer boulder rough opal direct from boulder opal mine or boulder opal cutters factory but opal mines stop work before xmas and some in November as temperature is too hot and working conditions are hot and dusty, some boulder opal miners do not start work till April so always plan ahead if you need boulder opal rough to cut and polish boulder potch is good to trial to see how good your polish is before polishing good quality opal rough. Bolder opal rough is also formed as veins in bedrock ironstone so once rough is faced a small nick from saw blade will force to rock to split open on this slit line and form two matching splits. Sometimes these splits are perfect and two matching opal earrings can be made from this boulder split.
